PH60874: MISSING UNLOADED ROWS WHEN USING ORDER BY CLAUSE AND UNLDDN CLAUSE. 24/04/18 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Regression introduced by HPU 5.1 APAR PH35906.
  
  Randomly, expected unloaded rows are missing when the following
  conditions are fulfilled:
  
   - unload in native mode
  
   - unload all rows from a tablespace using the UNLDDN feature
  
   - in the same UNLOAD command, a SELECT clause on a table from
  the tablespace unloaded by UNLDDN is specified with an ORDER BY
  clause.
  

Local fix

• If it is not mandatory, remove the ORDER BY clause.
  
  If the ORDER BY clause is mandatory, consider splitting the
  unload request in two distinct requests in two distinct HPU
  steps as indicated below:
  
  step 1:
  
  //HPU1 EXEC PGM=INZUTILB,
  
  ...
  
  //SYSIN  DD *
  
  
  
  UNLOAD TABLESPACE dbname.tsname
  
  UNLDDN ddn
  
  
  step 2
  
  
  //HPU2 EXEC PGM=INZUTILB,
  
  ...
  
  //SYSIN  DD *
  
  
  UNLOAD TABLESPACE
  
  
  SELECT col
  
  FROM table
  
  ORDER BY col
  
  OUTDDN ddn
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Db2 High Performance Unload for     *
  *                 z/OS                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: An output dataset containing the        *
  *                      unloaded data (UNLDDN, OUTDDN or both)  *
  *                      is incomplete. This occurs when all     *
  *                      the following conditions are fulfilled: *
  *                      - the unload is run either in Db2 HPU   *
  *                        5.1 with the fix for APAR PH35906     *
  *                        applied or in Db2 HPU 5.2             *
  *                      - the unload is processed in native     *
  *                        mode                                  *
  *                      - the same unload command requests both *
  *                      - a physical unload of the whole data   *
  *                        from a tablespace with the UNLDDN     *
  *                        option                                *
  *                      - a logical unload with an ORDER        *
  *                        clause against a table from           *
  *                        tablespace involved in the physical   *
  *                        unload                                *
  *                      - a timing condition regarding the      *
  *                        concurrent unload processes           *
  *                        (physical and logical) is fulfilled   *
  *                                                              *
  *                      Local fix: If applicable, remove the    *
  *                      ORDER clause. Otherwise, consider       *
  *                      splitting the unload request in two     *
  *                      distinct requests, one to create the    *
  *                      UNLDDN output and another one to        *
  *                      create the OUTDDN dataset, as in the    *
  *                      example below:                          *
  *                                                              *
  *                      Step 1                                  *
  *                                                              *
  *                         //HPU1 EXEC PGM=INZUTILB,            *
  *                                                              *
  *                         //SYSIN DD *                         *
  *                                                              *
  *                         UNLOAD TABLESPACE dbname.tsname      *
  *                         UNLDDN ddn                           *
  *                                                              *
  *                      Step 2                                  *
  *                                                              *
  *                         //HPU2 EXEC PGM=INZUTILB,            *
  *                                                              *
  *                         //SYSIN DD *                         *
  *                                                              *
  *                         UNLOAD TABLESPACE                    *
  *                                                              *
  *                         SELECT col                           *
  *                         FROM table                           *
  *                         ORDER BY col                         *
  *                         OUTDDN ddn                           *
  ****************************************************************
  * RECOMMENDATION: Apply the PTF                                *
  ****************************************************************
  missing rows from the unloaded data if physical unload (UNLDDN)
  and logical unload (OUTDDN) with ORDER clause against the same
  tablespace
  

Problem conclusion

• Code has been changed to fix this problem
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• INZ$$CCQ INZ$$PRM INZMQRY  INZPARM  INZTDSC  INZTOOLS INZTVAR
  INZUTIB1 INZUTIB2 INZUTILC INZUTILD INZUTILK
  

Fix information

• Fixed component name

  DB2 HI PERF UNL

• Fixed component ID

  5697F4400

Applicable component levels

• R510 PSY UI97393

     UP24/07/01 P F406 {

• R520 PSY UI97541

     UP24/07/03 P F407 {

Fix is available

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